An aspect has been known, in which a robot including a plurality of joints performs a series of operations of, in at least one of a plurality of work steps of a work line, receiving a workpiece having been subjected to work at an upstream side, performing work with respect to the workpiece, and sending the workpiece to a downstream side.
The robot moves based on, for example, a set position coordinate. However, if the position of the workpiece sent from the upstream side is not strict, subsequent work with respect to the workpiece cannot be appropriately performed. Especially, when a person performs the work at the upstream side and then places the workpiece at a position where the robot can receive the workpiece, the robot needs to perform position adjustment work of the workpiece.
The position adjustment of the workpiece by the robot has been performed in such a manner that: a predetermined positioning jig is provided in advance at a part of a stop position of the workpiece; and the robot holds the workpiece to, for example, bring the workpiece into contact with the positioning jig (see PTLs 1 and 2, for example).